U.S. patent application number 13/996882 was filed with the patent office on 2013-11-07 for substrate processing apparatus and method of manufacturing semiconductor device.
This patent application is currently assigned to Hitachi Kokusai Electric Inc.. The applicant listed for this patent is Tadashi Horie. Invention is credited to Tadashi Horie.
Application Number | 20130295768 13/996882 |
Document ID | / |
Family ID | 46314066 |
Filed Date | 2013-11-07 |
United States Patent
Application |
20130295768 |
Kind Code |
A1 |
Horie; Tadashi |
November 7, 2013 |
SUBSTRATE PROCESSING APPARATUS AND METHOD OF MANUFACTURING
SEMICONDUCTOR DEVICE
Abstract
A process chamber is provided into which a substrate is carried,
wherein a chlorine atom-containing metal nitride film, in which a
natural oxide film is formed on a top side thereof, is formed on
the substrate; a substrate support unit configured to support and
heat the substrate within the process chamber; a gas supply unit
configured to supply either or both of nitrogen atom-containing gas
and hydrogen atom-containing gas to an inside of the process
chamber; a gas exhaust unit configured to exhaust the gas from the
inside of the process chamber; a plasma generation unit configured
to excite the nitrogen atom-containing gas and the hydrogen
atom-containing gas supplied to the inside of the process chamber;
and a control unit configured to control the substrate support
unit, the gas supply unit, and the plasma generation unit.
Inventors: |
Horie; Tadashi; (Toyama-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Horie; Tadashi |
Toyama-shi |
|
JP |
|
|
Assignee: |
Hitachi Kokusai Electric
Inc.
Tokyo
JP
|
Family ID: |
46314066 |
Appl. No.: |
13/996882 |
Filed: |
December 22, 2011 |
PCT Filed: |
December 22, 2011 |
PCT NO: |
PCT/JP2011/079908 |
371 Date: |
June 21, 2013 |
Current U.S.
Class: |
438/685 ;
118/723R |
Current CPC
Class: |
H01L 21/67011 20130101;
H01L 21/76856 20130101; C23C 16/45553 20130101; C23C 16/56
20130101; H01L 21/0223 20130101; H01L 21/321 20130101; C23C 8/36
20130101; H01L 21/02068 20130101; H01L 28/40 20130101; C23C 16/34
20130101; H01L 21/28088 20130101; H01L 21/02697 20130101 |
Class at
Publication: |
438/685 ;
118/723.R |
International
Class: |
H01L 21/67 20060101
H01L021/67; H01L 21/02 20060101 H01L021/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2010 |
JP |
2010-285774 |
Claims
1. A substrate processing apparatus comprising: a process chamber
into which a substrate is carried, wherein a chlorine
atom-containing metal nitride film, in which a natural oxide film
is formed on a top side thereof, is formed on the substrate; a
substrate support unit configured to support and heat the substrate
within the process chamber; a gas supply unit configured to supply
either or both of nitrogen atom-containing gas and hydrogen
atom-containing gas to an inside of the process chamber; a gas
exhaust unit configured to exhaust the gas from the inside of the
process chamber; a plasma generation unit configured to excite the
gas supplied to the inside of the process chamber; and a control
unit configured to control the substrate support unit, the gas
supply unit, and the plasma generation unit.
2. The substrate processing apparatus according to claim 1, wherein
the metal nitride film is a titanium nitride film.
3. The substrate processing apparatus according to claim 1, wherein
the nitrogen atom-containing gas is any of a nitrogen gas, an
ammonia gas, and a monomethylhydrazine gas, and the hydrogen
atom-containing gas is any of a hydrogen gas, an ammonia gas, and a
monomethylhydrazine gas.
4. The substrate processing apparatus according to claim 1, wherein
a second electrode is provided on the substrate support unit, and
an impedance changing mechanism is connected to the substrate
support unit, and the control unit controls the impedance changing
mechanism so as to apply a voltage Vpp to the substrate.
5. A method of manufacturing a semiconductor device, the method
comprising: carrying a substrate into a process chamber and
supporting the substrate by a substrate support unit, wherein a
chlorine atom-containing metal nitride film, in which a natural
oxide film is formed on a top side thereof, is formed on the
substrate; heating the substrate by the substrate support unit;
supplying, by a gas supply unit, either or both of nitrogen
atom-containing gas and hydrogen atom-containing gas to an inside
of the process chamber; and exciting, by a plasma generation unit,
the gas supplied to the inside of the process chamber.
Description
TECHNICAL FIELD
[0001] The present invention relates to a substrate processing
apparatus that processes a substrate using plasma, and a method of
manufacturing a semiconductor device.
BACKGROUND ART
[0002] In a semiconductor logic device, a DRAM device and the like,
in order to suppress an increase in an electric resistance
accompanying down-scaling, a metal nitride film for example
containing titanium nitrides (hereafter simply referred to as
titanium nitride (TiN) film) is employed as a material of
electrodes, wirings and the like. The metal nitride film can be
formed for example by a chemical vapor deposition (CVD) method, or
an atomic layer deposition (ALD) method. In order to form the
titanium nitride film by such methods, a titanium tetrachloride
(TiCl.sub.4) gas containing chlorines is used as a precursor gas. A
method of forming the titanium nitride film is described for
example in Patent Document 1.
CITATION LIST
Patent Document
[0003] Patent Document 1: WO2007/020874
SUMMARY
Problems to be Solved by the Invention
[0004] However, it has been found by a research of the inventors
that impurities such as chlorine atoms, carbon atoms and the like
remain in a film when a titanium nitride film is formed by the
aforementioned methods. Especially, in a case of using a titanium
tetrachloride gas as a precursor gas, chlorine atom residues in the
titanium nitride film become prominent. Residual substances such as
the chlorine atoms, the carbon atoms and the like increase an
electric resistance of the titanium nitride film, and it becomes
difficult to form a film that satisfies properties required in
down-scaling of integrated circuits and in improving device
properties in the recent years.
[0005] The chlorine atoms can be removed by forming the titanium
nitride film under a high temperature, or by performing a high
temperature treatment on the titanium nitride film after having
formed the same. However, if the high temperature treatment is
performed on titanium nitride films formed for example for an upper
electrode and a lower electrode of a DRAM capacitor, properties of
a capacitance insulating film and the like sandwiched by the
titanium nitride films are deteriorated, whereby in some cases a
leak current is increased. Further, in some cases, a circuit
property may be deteriorated due to an occurrence of diffusion in a
source region and a drain region formed on a substrate in advance,
whereby a performance of a semiconductor device may be reduced.
Nonetheless, if a process of removing the chlorine atoms is
performed in a temperature range by which the aforementioned
property deterioration and diffusion would not occur, it then
becomes difficult to sufficiently remove the residual
chlorines.
[0006] Further, a surface of the titanium nitride film is naturally
oxidized, and is of a layer containing a large content of oxygen
atoms. The oxygen atoms remaining in the titanium nitride film
increase the electric resistance of the titanium nitride film.
Further, the oxygen atoms change an interfacial property of the
titanium nitride film and the capacitance insulating film and the
like formed on top thereof, and deteriorate device properties.
[0007] Further, in a case of forming the upper electrode and the
lower electrode of the DRAM by the titanium nitride films, although
a metal oxide film and the like that is the capacitance insulating
film is formed after having formed the titanium nitride film as the
lower electrode, in some cases the titanium nitride film as the
lower electrode is oxidized upon forming the metal oxide film, and
the device properties may thereby be deteriorated.
[0008] An object of the present invention is to provide a metal
processing apparatus, and a method of manufacturing a semiconductor
device that can achieve one or both of reducing a chlorine atom
residual amount and an oxygen atom residual amount in a metal
nitride film and improving an oxidation resistance property of the
metal nitride film in a temperature range by which properties of
other films adjacent to the metal nitride film are not
deteriorated.
Solutions to Problems
[0009] According to one embodiment, there is provided a substrate
processing apparatus including: a process chamber into which a
substrate is carried, wherein a chlorine atom-containing metal
nitride film, in which a natural oxide film is formed on a top side
thereof, is formed on the substrate; a substrate support unit
configured to support and heat the substrate within the process
chamber; a gas supply unit configured to supply either or both of
nitrogen atom-containing gas and hydrogen atom-containing gas to an
inside of the process chamber; a gas exhaust unit configured to
exhaust the gas from the inside of the process chamber; a plasma
generation unit configured to excite the gas supplied to the inside
of the process chamber; and a control unit configured to control
the substrate support unit, the gas supply unit, and the plasma
generation unit.
[0010] According to another embodiment, there is provided a method
of manufacturing a semiconductor device, the method including:
carrying a substrate into a process chamber and supporting the
substrate by a substrate support unit, wherein a chlorine
atom-containing metal nitride film, in which a natural oxide film
is formed on a top side thereof, is formed on the substrate;
heating the substrate by the substrate support unit; supplying, by
a gas supply unit, either or both of nitrogen atom-containing gas
and hydrogen atom-containing gas to an inside of the process
chamber; and exciting, by a plasma generation unit, the gas
supplied to the inside of the process chamber.
Effects
[0011] According to the substrate processing apparatus and the
method of manufacturing a semiconductor device according to the
invention, residual amounts of chlorine atoms and oxygen atoms in
the metal nitride film can be reduced in a temperature range in
which properties of other films adjacent to the metal nitride film
are not deteriorated, and an oxidation resistance can be improved
while improving properties of the metal nitride film.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is a schematic cross-sectional view of a substrate
processing apparatus that performs a method of manufacturing a
semiconductor device according to an embodiment.
[0013] FIG. 2 is a graph showing an example of a concentration of
chlorine atoms in a titanium nitride film.
[0014] FIG. 3 is a graph showing a temperature dependence of a
sheet resistance of the titanium nitride film.
[0015] FIG. 4 is a graph showing an example of a change in the
sheet resistance of the titanium nitride film.
[0016] FIG. 5 is a table showing a composition ratio of the
titanium nitride film.
[0017] FIG. 6 is a graph showing an example of the change in the
sheet resistance of the titanium nitride film upon being exposed to
an oxygen atmosphere.
[0018] FIG. 7 is a graph showing an example of a change in a sheet
resistance ratio when processing is performed by changing a ratio
between a nitrogen gas and a hydrogen gas.
[0019] FIG. 8 is a graph showing an example of the change in the
sheet resistance ratio when processing is performed by changing a
ratio between the nitrogen gas and an ammonia gas.
[0020] FIG. 9 is a graph showing an example of a change in
TiO.sub.x and TiN.sub.x concentrations within a film when
processing is performed by changing a voltage Vpp of a second
electrode.
[0021] FIG. 10 is a graph showing an example of a change in a
chlorine concentration within the film when processing is performed
by changing the voltage Vpp of the second electrode.
DESCRIPTION OF EMBODIMENT
[0022] As described above, when high temperature processing for
example at 750.degree. C. or more is performed on a titanium
nitride film, properties of other films adjacent to the titanium
nitride film are deteriorated, and in some cases a leaking current
of a capacitor of a DRAM for example may be increased. Further,
there may be cases where a circuit property is deteriorated by
diffusions occurring in a source region and a drain region formed
in advance on a substrate, and a performance of a semiconductor
device is decreased. On the other hand, if a process of removing
chlorine atoms is performed in a temperature range in which the
properties of the films adjacent to the titanium nitride film are
not deteriorated, it becomes difficult to sufficiently remove
residual chlorine.
[0023] In regards to this, the inventors have conducted intensive
studies on a method of improving an oxidation resistance of a
titanium nitride film while reducing the residual amounts of
chlorine and oxygen within the titanium nitride film in the
temperature range in which the properties of the other films
adjacent to the titanium nitride film are not deteriorated. As a
result, the inventors have found that the above problem can be
solved by activating a gas, in which a hydrogen atom-containing gas
is mixed with a nitrogen atom-containing gas, by using plasma, and
supplying the activated gas to the titanium nitride film formed on
the substrate. The invention has been made based on the above
discovery achieved by the inventors. An embodiment will be
described below.
(1) Configuration of Substrate Processing Apparatus
[0024] First, an exemplary configuration of a substrate processing
apparatus that performs a method of manufacturing a semiconductor
device of the embodiment will be described with reference to FIG.
1. FIG. 1 is a cross-sectional configuration diagram of an MMT
apparatus as the substrate processing apparatus. The MMT apparatus
uses a modified magnetron typed plasma source that can generate
highly concentrated plasma by an electric field and a magnetic
field. The MMT apparatus is, for example, an apparatus that
performs plasma processing on a silicon substrate 100 such as a
silicon wafer.
[0025] The MMT apparatus includes a processing furnace 202 that
performs plasma processing on the silicon substrate 100. The
processing furnace 202 includes a processing container 203 that
configures a process chamber 201, a susceptor 217, a gate valve
244, a shower head 236, a gas exhaust opening 235, a cylindrical
electrode 215, an upper magnet 216a, a lower magnet 216b, and a
controller 121.
[0026] The processing container 203 configuring the process chamber
201 includes a dome-shaped upper container 210 that is a first
container, and a bowl-shaped lower portion container 211 that is a
second container. Further, the process chamber 201 is formed by the
lower container 211 being covered with the upper container 210. The
upper container 210 is formed of a nonmetallic material such as
aluminum oxide (Al.sub.2O.sub.3) or quartz (SiO.sub.2), and the
lower container 211 is formed of, for example, aluminum (Al).
[0027] A susceptor 217 supporting the silicon substrate 100 is
disposed at the center on a bottom side in the process chamber 201.
The susceptor 217 is formed of a nonmetallic material such as
aluminum nitride (AlN), ceramics, or quartz so as to reduce
metallic contamination of a film formed on the silicon substrate
100.
[0028] A heater 217b as a heating mechanism is integrally embedded
inside the susceptor 217, and is configured to heat the silicon
substrate 100. When power is supplied to the heater 217b, it is
capable of heating a surface of the silicon substrate 100 to, for
example, about 200 to 750.degree. C.
[0029] A substrate support unit of the embodiment mainly includes
the susceptor 217, the heater 217b, and a second electrode
217c.
[0030] The susceptor 217 is electrically insulated from the lower
container 211. A second electrode (not shown) as an electrode for
changing an impedance is installed inside the susceptor 217. The
second electrode is arranged via an impedance changing mechanism
274. The impedance changing mechanism 274 includes coils and
variable capacitors, and is configured to control a potential of
the silicon substrate 100 via the second electrode 217c and the
susceptor 217 by controlling a pattern number of coils and capacity
values of the variable capacitors.
[0031] A susceptor lifting mechanism 268 for lifting and lowering
the susceptor 217 is provided in the susceptor 217. The susceptor
217 has through holes 217a provided therein. At least three wafer
push-up pins 266 for pushing the silicon substrate 100 upward are
provided on a bottom surface of the aforementioned lower container
211. Further, the through holes 217a and the wafer push-up pins 266
are arranged relative to one another so that the wafer push-up pins
266 penetrate the through holes 217a without coming into contact
with the susceptor 217 when the susceptor 217 is lowered by the
susceptor lifting mechanism 268.
[0032] A gate valve 244 as a gate valve is provided on a side wall
of the lower container 211. When the gate valve 244 is open, the
silicon substrate 100 can be introduced into the process chamber
201 by using a transfer mechanism (not shown), or the silicon
substrate 100 can be taken out of the process chamber 201. By
closing the gate valve 244, the process chamber 201 can be
airtightly closed.
[0033] The shower head 236 for supplying a gas into the process
chamber 201 is provided at an upper portion of the process chamber
201. The shower head 236 includes a cover body 233 on a cap, a gas
inlet 234, a buffer chamber 237, an opening 238, a blocking plate
240, and a gas outlet 239.
[0034] A downstream end of a gas supplying pipe 232 for supplying a
gas into the buffer chamber 237 is connected to the gas inlet 234
via an O-ring 203b as a sealing member. The buffer chamber 237
functions as a dispersing space for dispersing the gas introduced
through the gas inlet 234.
[0035] A downstream end of a nitrogen gas supplying pipe 232a for
supplying an N.sub.2 gas as a nitrogen atom-containing gas, a
downstream end of a hydrogen gas supplying pipe 232b for supplying
an H.sub.2 gas as a hydrogen atom-containing gas, and a downstream
end of a noble gas supplying pipe 232c for supplying a noble gas
such as helium (He) and argon (Ar) as a dilution gas are connected
to, and joined at, an upstream side of the gas supplying pipe
234.
[0036] A nitrogen gas cylinder 250a, a mass flow controller 251a as
a flow rate controlling apparatus, and a valve 252a as an on-off
valve are connected to the nitrogen gas supplying pipe 232a in
order from an upstream side. A hydrogen gas cylinder 250b, a mass
flow controller 251b as a flow rate controlling apparatus, and a
valve 252b as an on-off valve are connected to the hydrogen gas
supplying pipe 232b in order from an upstream side. A noble gas
cylinder 250c, a mass flow controller 251c as a flow rate
controlling apparatus, and a valve 252c as an on-off valve are
connected to the noble gas supplying pipe 232c in order from an
upstream side.
[0037] A gas supply unit of the embodiment mainly includes the gas
supplying pipe 234, the nitrogen gas supplying pipe 232a, the
hydrogen gas supplying pipe 232b, the noble gas supplying pipe
232c, the nitrogen gas cylinder 250a, the hydrogen gas cylinder
250b, the noble gas cylinder 250c, the mass flow controllers 251a
to 252c, and the valves 252a to 252c. The gas supplying pipe 234,
the nitrogen gas supplying pipe 232a, the hydrogen gas supplying
pipe 232b, and the noble gas supplying pipe 232c are formed of a
nonmetallic material such as quartz or aluminum oxide, and a
metallic material such as SUS. The gas supplying pipes are
configured to arbitrarily supply the N.sub.2 gas, the H.sub.2 gas,
and the noble gas into the process chamber 201 via the buffer
chamber 237 by opening and closing of these valves 252a to 252c and
flow rate control by the mass flow controllers 251a to 252c.
[0038] Although a case of providing the gas cylinder for each of
the N.sub.2 gas, the H.sub.2 gas, and the noble gas has been
described here, the invention is not limited to such an embodiment,
and an ammonia (NH.sub.3) gas cylinder may be provided instead of
the nitrogen gas cylinder 250a and the hydrogen gas cylinder 250b.
Further, to increase a ratio of nitrogen in a reactant gas supplied
into the process chamber 201, an N.sub.2 gas cylinder may further
be provided to add the N.sub.2 gas to the NH.sub.3 gas.
[0039] A gas exhaust opening 235 for exhausting the reactant gas
and the like from the process chamber 201 is provided on a lower
portion of the side wall of the lower container 211. An upstream
end of a gas exhaust pipe 231 for exhausting a gas is connected to
the gas exhaust opening 235. An APC 242 that is a pressure
regulator, a valve 243b that is an on-off valve, and a vacuum pump
246 that is an exhaust apparatus are provided on the gas exhaust
pipe 231 in order from an upstream side. A gas exhaust unit of the
embodiment mainly includes the gas exhaust opening 235, the gas
exhaust pipe 231, the APC 242, the valve 243b, and the vacuum pump
246. The gas exhaust unit is configured to exhaust the interior of
the process chamber 201 by activating the vacuum pump 246 and
opening the valve 243b. Further, the gas exhaust unit is configured
to adjust a pressure value inside the process chamber 201 by
adjusting a divergence of the APC 242.
[0040] A cylindrical electrode 215 as a first electrode is provided
on an outer periphery of the processing container 203 (upper
container 210) so as to surround a plasma generating region 224
within the process chamber 201. The cylindrical electrode 215 is
formed cylindrically, for example, in the form of a round cylinder.
The cylindrical electrode 215 is connected, via an impedance
matching box 272 that performs matching of impedances, to a high
frequency power source 273 that generates high frequency power. The
cylindrical electrode 215 functions as a discharge mechanism that
excites the gas to be supplied into the process chamber 201 to
thereby generate plasma.
[0041] An upper magnet 216a and a lower magnet 216b are
respectively attached to upper and lower end portions on an outer
surface of the cylindrical electrode 215. The upper magnet 216a and
the lower magnet 216b are each configured as a permanent magnet
formed cylindrically, for example, in the form of a ring.
[0042] The upper magnet 216a and the lower magnet 216b each include
magnetic poles on both ends along a radial direction of the process
chamber 201 (that is, on an inner circumferential end and an outer
circumferential end of each magnet). Orientations of the magnetic
poles of the upper magnet 216a and the lower magnet 216b are
disposed so as to be opposite to one another. That is, the magnetic
poles on inner circumferential portions of the upper magnet 216a
and the lower magnet 216b are of different poles. Due to this, a
line of magnetic force in a cylindrical axis direction is formed
along an inner surface of the cylindrical electrode 215.
[0043] A plasma generation unit of the embodiment mainly includes
the cylindrical electrode 215, the impedance matching box 272, the
high frequency power source 273, the upper magnet 216a, and the
lower magnet 216b. By forming an electric field by supplying the
high frequency power to the cylindrical electrode 215, and forming
a magnetic field by using the upper magnet 216a and the lower
magnet 216b after having introduced a mixed gas of the N.sub.2 gas
and the H.sub.2 gas into the process chamber 201, magnetron
discharge plasma is generated in the process chamber 201. At this
occasion, an ionization rate of the plasma is increased by the
aforementioned electromagnetic field causing discharged electrons
to move orbitally, and the plasma with long life and high density
can be generated.
[0044] Note that a metallic blocking plate 223 for effectively
blocking the electromagnetic field is provided around the
cylindrical electrode 215, the upper magnet 216a, and the lower
magnet 216b so that the electromagnetic field formed thereby does
not adversely affect an external environment or an apparatus such
as another processing furnace.
[0045] Further, the controller 121 as a control unit is configured
to control the APC 242, the valve 243b, and the vacuum pump 246
through a signal line A, to control the susceptor lifting mechanism
268 through a signal line B, to control the gate valve 244 through
a signal line C, to control the impedance matching box 272 and the
high frequency power source 273 through a signal line D, to control
the mass flow controllers 251a to 252c and the valves 252a to 252c
through a signal line E, and further to control a heater embedded
in the susceptor and the impedance changing mechanism 274 through a
signal line not shown.
(2) Substrate Processing Step
[0046] Next, a substrate processing step that is performed as one
of the steps in a semiconductor manufacturing step of the
embodiment will be described. This step is performed by the
aforementioned MMT apparatus as the substrate processing apparatus.
Note that in the following description, operations of respective
units configuring the MMT apparatus are controlled by the
controller 121. Here, an example in which a metal nitride film
(titanium nitride film) formed as a lower electrode of a capacitor
is subjected to nitriding by using plasma will be described.
(Introduction of Substrate)
[0047] First, the susceptor 217 is lowered to a transporting
position of the silicon substrate 100, and the wafer push-up pins
266 are inserted into the through holes 217a of the susceptor 217.
As a result, the push-up pins 266 protrude from a surface of the
susceptor 217 by a predetermined height.
[0048] Then, the gate valve 244 is opened, and the silicon
substrate 100 is introduced into the process chamber 201 by using a
transporting mechanism that is not shown. As a result, the silicon
substrate 100 is horizontally supported on the wafer push-up pins
266 protruding from the surface of the susceptor 217. On the
silicon substrate 100, the titanium nitride film as the lower
electrode of the capacitor is formed in advance by a CVD method or
an ALD method. The titanium nitride film is formed by another CVD
apparatus or ALD apparatus (not shown) using a titanium
tetrachloride (TiCl.sub.4) gas containing chlorines as a precursor
gas. Note that since the titanium tetrachloride gas is used as the
precursor gas, chlorine atoms are remaining in the titanium nitride
film. Further, a natural oxide film is formed on a surface of the
titanium nitride film. The natural oxide film is formed when the
silicon substrate 100 is introduced into the process chamber 201
from the aforementioned CVD apparatus or ALD apparatus.
[0049] Upon introducing the silicon substrate 100 into the process
chamber 201, the transporting mechanism is evacuated to the outside
of the process chamber 201, and the process chamber 201 is sealed
by closing the gate valve 244. Then, by using the susceptor lifting
mechanism 268, the susceptor 217 is lifted. As a result, the
silicon substrate 100 is disposed on an upper surface of the
susceptor 217. Thereafter, the susceptor 217 is lifted to a
predetermined position, and the silicon substrate 100 is lifted to
a predetermined processing position.
[0050] Note that, to introduce the silicon substrate 100 into the
process chamber 201, it is preferable to supply the N.sub.2 gas and
the noble gas as inactive gases from a gas supplying line to fill
the process chamber 201 with the inactive gases, and reduce an
oxygen concentration while the process chamber 201 is exhausted by
a gas exhaust line. That is, it is preferable to supply the
inactive gas into the process chamber 201 via the buffer chamber
237 by opening the valve 243a or the valve 243c while the process
chamber 201 is exhausted by activating the vacuum pump 246 and
opening the valve 243b.
(Temperature Rise in Substrate)
[0051] Next, power is supplied to a heater 217h embedded inside the
susceptor 217, and the surface of the silicon substrate 100 is
heated. A surface temperature of the silicon substrate 100 is
preferably a temperature that is 200.degree. C. or more and less
than 750.degree. C., more preferably 200.degree. C. or more and
700.degree. C. or less.
[0052] Note that, in a heating process of the silicon substrate
100, when the surface temperature is heated to 750.degree. C. or
more, diffusion occurs in a source region and a drain region formed
in the silicon substrate 100, which may deteriorate a circuit
property and decrease a performance of a semiconductor device. By
limiting the temperature of the silicon substrate 100 as above, the
diffusion of impurities in the source region and the drain region
formed in the silicon substrate 100, the deterioration of the
circuit property, and the decrease in the performance of the
semiconductor device can be suppressed. In the following
description, the surface temperature of the silicon substrate 100
is set at, for example, 450.degree. C.
(Introduction of Reactant Gas)
[0053] Here, an example of using a mixed gas of the N.sub.2 gas and
the H.sub.2 gas as the reactant gas will be described.
[0054] First, the valves 252a and 252b are opened to introduce
(supply) the reactant gas that is the mixed gas of the N.sub.2 gas
and the H.sub.2 gas into the process chamber 201 via the buffer
chamber 237. At this occasion, divergences of the mass flow
controllers 251a and 251b are respectively controlled so as to
cause a flow rate of the N.sub.2 gas included in the reactant gas
and a flow rate of the H.sub.2 gas included in the reactant gas
become predetermined flow rates. The flow rate of the H.sub.2 gas
to be supplied into the process chamber 201 is in a range of 0 sccm
or more and 600 sccm or less. Further, the flow rate of the N.sub.2
gas to be supplied into the process chamber 201 is in a range of 0
sccm or more and 600 sccm or less. Note that, in this occasion, the
valve 252c may be opened to supply the noble gas as the dilution
gas into the process chamber 201, and a concentration of the mixed
gas of the N.sub.2 gas and the H.sub.2 gas to be supplied into the
process chamber 201 may be adjusted. A ratio of nitrogen atoms to
hydrogen atoms contained in the gases supplied into the process
chamber 201 is in a range of 0 or more and 100 or less.
[0055] Further, after having started the introduction of the
reactant gas into the process chamber 201, the vacuum pump 246 and
the APC 242 are used to adjust a pressure within the process
chamber 201 to be in a range of 0.1 to 300 Pa, more preferably 0.1
to 100 Pa, for example 30 Pa.
(Excitation of Reactant Gas)
[0056] After having started the introduction of the reactant gas,
magnetron discharge is generated in the process chamber 201 by
applying high frequency power to the cylindrical electrode 215 from
the high frequency power source 273 via the impedance matching box
272, and applying a magnetic force by the upper magnet 216a and the
lower magnet 216b into the process chamber 201. As a result, highly
concentrated plasma is generated in the plasma generating region
224 above the silicon substrate 100. Note that the power to be
applied to the cylindrical electrode 215 is in a range of, for
example, 100 to 3000 W, for example, 800 W. At this occasion, a
voltage Vpp can be applied to the silicon substrate 100 via the
second electrode 217c provided on the susceptor 217. The voltage
Vpp is controlled by the impedance changing mechanism 274 connected
to the second electrode 217c. An impedance value (voltage Vpp) is
controlled beforehand to a desired value after having introduced
the substrate.
[0057] By forming a plasma state as aforementioned, the N.sub.2 gas
and the H.sub.2 gas supplied into the process chamber 201 are
excited and activated. Further, nitrogen radicals (N*) and hydrogen
radicals (H*) generated thereby react with the surface of the
silicon substrate 100. In this reaction, reduction by the hydrogen,
and collision and replenishment of nitrogen atoms to the surface of
the titanium nitride film are performed. As a result, a hydrogen
chloride gas is generated by the reaction between chlorine
components and the hydrogen, and an aqueous (H.sub.2O) gas is
generated by the reaction between oxygen components and the
hydrogen. Both of the generated gases are discharged to the outside
of the titanium nitride film. Further, the nitrogen atoms are
introduced into the titanium nitride film, and the titanium nitride
film with a stronger bonding degree is formed. Chemical reaction
formulas in the reaction are shown below.
TiCl+N*+H*.fwdarw.*TiN+HCl.uparw. (Formula 1)
TiO+N*+2H*.fwdarw.*TiN+H.sub.2O.uparw. (Formula 2)
(Exhaust of Residual Gas)
[0058] When the nitriding of the titanium nitride film has ended,
the power supply to the cylindrical electrode 215 is stopped, and
the valves 252a and 252b are closed to stop the gas supply into the
process chamber 201. Then, the residual gas within the process
chamber 201 is exhausted using the gas exhaust pipe 231. Further,
the susceptor 217 is lowered to the transporting position of the
silicon substrate 100, and causes the silicon substrate 100 to be
supported on the wafer push-up pins 266 protruding from the surface
of the susceptor 217. Then, the gate valve 244 is opened, the
silicon substrate 100 is taken out of the process chamber 201 by
using the transporting mechanism that is not shown, and the
substrate processing step of the embodiment ends.
(3) Advantageous Effects of the Embodiment
[0059] According to the embodiment, one or more of the advantageous
effects described below can be achieved.
[0060] (a) According to the embodiment, the residual amount of the
chlorine atoms in the titanium nitride film can be reduced, a
quality of the titanium nitride film can be improved, and an
electric resistance of the titanium nitride film can be
reduced.
[0061] FIG. 2 is a graph showing the concentration of the chlorine
atoms in the titanium nitride film before and after the
aforementioned substrate processing step. A vertical axis of FIG. 2
shows a density (atomic %) of the chlorine atoms in the titanium
nitride film, and a horizontal axis shows a depth (nm) from the
surface of the titanium nitride film. According to FIG. 2, it can
be understood that the density of the chlorine atoms is decreased
from the surface of the titanium nitride film to the depth of about
4 nm. That is, it can be understood that the residual amount of the
chlorine atoms in the titanium nitride film can be reduced by
performing the aforementioned substrate processing step.
[0062] (b) According to the embodiment, the residual amount of the
oxygen atoms in the titanium nitride film can be reduced, and the
electric resistance of the titanium nitride film can be reduced.
Further, introduction of the nitrogen atoms into the titanium
nitride film is enhanced, whereby the bonding degree of the
titanium nitride film can be increased, and the electric resistance
of the titanium nitride film can be reduced.
[0063] FIG. 5 is a result of evaluating a composition ratio of the
titanium nitride film before and after the aforementioned substrate
processing step by an X-ray photoelectron spectroscopy method. In
this measurement, a composition at the depth of about 4 nm from the
surface of the titanium nitride film is analyzed. According to FIG.
5, it can be understood that the composition ratio of the oxygen
atoms is reduced, and the composition ratios of the nitrogen atoms
and titanium atoms are each increased. That is, it can be
understood that, by performing the aforementioned substrate
processing step, the titanium nitride film with stronger bonding
degree is formed by the oxygen atoms in the titanium nitride film
being removed and nitriding of the titanium nitride film being
enhanced due to the introduction of the nitrogen atoms into the
titanium nitride film. Further, it can also be understood that the
residual amount of carbon atoms is reduced.
[0064] (c) According to the embodiment, the aforementioned
substrate processing step is performed at a temperature of
200.degree. C. or more and less than 750.degree. C. (hereinafter
referred to as a processing temperature region), or preferably at a
temperature of 200.degree. C. or more and 700.degree. C. or less.
As a result, the electric resistance of the titanium nitride film
can be reduced, and a property thereof can be improved.
[0065] FIG. 3 is a graph showing a temperature dependence of a
sheet resistance of the titanium nitride film when the substrate
process is performed at a temperature including the aforementioned
processing temperature region. In FIG. 3, a ratio of the sheet
resistance (sheet resistance changing ratio) of the titanium
nitride film after having performed the substrate processing step
with the sheet resistance (.OMEGA./square) of the titanium nitride
film before performing the aforementioned substrate process as 1
(reference). The processing temperature (surface temperature of the
silicon substrate 100) is set at a room temperature to 700.degree.
C., and the plasma processing is performed by using the mixed gas
of the N.sub.2 gas and the H.sub.2 gas. According to FIG. 3, it can
be understood that the sheet resistance changing rate becomes 1 or
less when the processing temperature is set to be 200.degree. C. or
more. It can be therefore understood that a film quality is
improved better as the processing temperature is set higher as well
as 200.degree. C. or more. However, when the processing is
performed at a temperature of 750.degree. C. or more, there is a
problem in that the performance of the semiconductor device formed
on the silicon substrate 100 is decreased. This problem is caused
by the diffusion occurring in the source region and the drain
region, and the circuit property being deteriorated. Thus, in the
present process, it is preferable to set the processing temperature
to be 200.degree. C. or more and less than 750.degree. C.
[0066] FIG. 4 is a graph showing a change in the sheet resistance
of the titanium nitride film when the aforementioned substrate
processing step is performed. In FIG. 4, the ratio of the sheet
resistance (sheet resistance ratio) of the titanium nitride film
after having performed the substrate processing step with the sheet
resistance (.OMEGA./square) of the titanium nitride film before
performing the aforementioned substrate processing step as 1
(reference). Note that in FIG. 4(a), the processing temperature
(surface temperature of the silicon substrate 100) is set at the
room temperature, and the plasma processing is performed by using a
mixed gas of the N.sub.2 gas and an NH.sub.3 gas. In FIG. 4(b), the
processing temperature is set at 260.degree. C., and the plasma
processing is performed by using the mixed gas of the N.sub.2 gas
and the NH.sub.3 gas. In FIG. 4(c), the processing temperature is
set at 450.degree. C., and the plasma processing is performed by
using the mixed gas of the N.sub.2 gas and the NH.sub.3 gas. In
FIG. 4(d), the processing temperature is set at 450.degree. C., and
the plasma processing is performed by using only the N.sub.2
gas.
[0067] According to FIG. 4, in all of the cases where the
processing temperature is set to a temperature in the processing
temperature region (cases of FIG. 4(b) to (d)), it can be
understood that the sheet resistance can be reduced by performing
the aforementioned substrate processing step. Contrary to this, in
the case where the processing temperature is set to the room
temperature (case of FIG. 4(a)), it can be understood that the
sheet resistance is increased by performing the plasma
processing.
[0068] Note that, as shown in FIG. 4(b), by using the mixed gas of
the N.sub.2 gas and the NH.sub.3 gas as the reactant gas, it can be
understood that similar or greater advantageous effects to/than (d)
in FIG. 4 setting the processing temperature at 450.degree. C. can
be achieved in an atmosphere of only the N.sub.2 gas, despite the
processing temperature being low, namely, 260.degree. C. This is
assumed to result from a hydrogen component included in the
NH.sub.3 gas enhancing the removal of chlorine atoms remaining in
the titanium nitride film.
[0069] Further, as shown in FIG. 4(c), it can be understood that,
by using the mixed gas of the N.sub.2 gas and the NH.sub.3 gas as
the reactant gas and increasing the processing temperature to
450.degree. C., the sheet resistance ratio can more effectively be
reduced. That is, it can be understood that, by increasing the
processing temperature, the removal of the chlorine atoms from the
silicon nitride film can be enhanced. However, such high
temperature processing needs to be performed in the temperature
range that does not deteriorate a property of films adjacent to the
titanium nitride film (that is, at a temperature of 200.degree. C.
or more and less than 750.degree. C. (processing temperature
region), more preferably at a temperature of 200.degree. C. or more
and 700.degree. C. or less).
[0070] (d) According to the embodiment, an oxidation resistance of
the titanium nitride film can be improved. As a result, natural
oxidization of the titanium nitride film can be suppressed, and the
electric resistance of the titanium nitride film can be reduced.
Further, to form a metal oxide film and the like as a capacitance
insulating film by using an oxidizing agent such as O.sub.2 or
O.sub.3 on the titanium nitride film as the lower electrode of the
DRAM, the oxidization of the titanium nitride film by the oxidizing
agent can be suppressed, and an interfacial quality can be
improved.
[0071] FIG. 6 is a graph showing a change in the sheet resistance
of the titanium nitride film upon being exposed to an oxygen
(O.sub.2) atmosphere. Note that the exposure to the oxygen
(O.sub.2) atmosphere was performed for 120 seconds with an O.sub.2
gas atmosphere, a gas pressure of 200 Pa, and a wafer temperature
of 450.degree. C. FIG. 6(a) shows the change in the sheet
resistance ratio of the titanium nitride film to which the
aforementioned substrate processing step has not been performed,
FIG. 6(b) shows the change in the sheet resistance ratio of the
titanium nitride film to which the aforementioned substrate
processing step has been performed. Both of them set a value of the
sheet resistance of the titanium nitride film to which the
aforementioned substrate processing step has not been performed and
that is before being exposed to the oxygen atmosphere as 1
(reference).
[0072] As shown in FIG. 6, it can be understood that the sheet
resistance of the titanium nitride film is reduced by 24% by
performing the aforementioned substrate processing step. Further,
although the sheet resistance of the titanium nitride film
increases by being exposed to the oxygen atmosphere, it can be
understood that an increase in the sheet resistance is suppressed
in the titanium nitride film to which the aforementioned substrate
processing step has been performed compared to the titanium nitride
film to which the substrate processing step has not been performed.
That is, it can be understood that the increase in the value of the
sheet resistance in the titanium nitride film to which the
substrate processing step has not been performed is 14%, whereas in
the titanium nitride film to which the substrate processing step
has been performed, the increase in the value of the sheet
resistance is suppressed to 9%. Accordingly, it can be understood
that an oxidation resistance of the titanium nitride film can be
improved by performing the aforementioned substrate processing
step.
[0073] (e) Further, according to the embodiment, the highly
concentrated plasma is generated in the vicinity of the silicon
substrate 100, that is, in the plasma generating region 224 above
the silicon substrate 100, and the nitrogen radicals (N*) and the
hydrogen radicals (H*) are generated inside the process chamber
201. Therefore, the generated radicals can effectively be supplied
to the titanium nitride film before being deactivated. Further, a
processing speed of the aforementioned substrate processing
(nitriding using the plasma) can be improved. Note that in a remote
plasma method of generating plasma outside the process chamber 201
to generate radicals thereat, the generated radicals tend to be
deactivated before being supplied to the silicon substrate 100, and
it is difficult to effectively supply the radicals to the silicon
substrate 100.
[0074] (f) Further, as a result of intensive studies, it has been
found that a property of a thin film to be formed can be changed by
performing the processing by changing a ratio of the nitrogen gas
to the hydrogen gas in the processing gas. Hereinbelow, a
modification of the sheet resistance ratio in the case of changing
the ratio of the nitrogen gas in the processing gas will be
described.
[0075] FIG. 7 shows a graph comparing the sheet resistance ratio of
the thin film processed by changing the ratio between the nitrogen
gas (N.sub.2) and the hydrogen gas (H.sub.2), the sheet resistance
ratio of the processed thin film after being exposed to the oxygen
atmosphere, and the sheet resistance ratio of the thin film that
has been exposed to the oxygen atmosphere without being subjected
to the aforementioned nitriding. Note that the exposure to the
oxygen (O.sub.2) atmosphere was performed for 120 seconds with the
O.sub.2 gas atmosphere, the gas pressure of 200 Pa, and the wafer
temperature of 450.degree. C. In any case, the value of the sheet
resistance of the titanium nitride film to which the aforementioned
substrate processing step has not been performed and that is before
being exposed to the oxygen atmosphere is set as 1 (reference).
[0076] As shown in FIG. 7, it can be understood that the sheet
resistance of the titanium nitride film can be reduced by
performing the aforementioned substrate processing step. Further,
the sheet resistance ratio becomes 0.89 or less in a range where
the ratio of nitrogen gas to hydrogen in the processing gas is 0 or
more and 0.75 or less, and the sheet resistance ratio can more
effectively be reduced, whereby a refinement of integrated circuits
and a property required in a semiconductor device in recent years
can be realized. Further, even with the thin film that has been
exposed to the oxygen atmosphere after the nitriding, the sheet
resistance ratio becomes about 0.92 or less when the ratio of
nitrogen gas to hydrogen in the processing gas in performing the
nitriding is in a range of larger than 0 and 0.75 or less, and the
property can be maintained even if an oxide film is formed on the
titanium nitride film. Accordingly, it can be understood that, by
performing the aforementioned substrate processing step, not only
the reduction in the electric resistance of the titanium nitride
film but also the oxidation resistance can be improved. Further, as
seen from FIG. 7, in a process in which the ratio of the nitrogen
gas to the hydrogen in the processing gas is 0, that is, in a
process performed with the ratio of the hydrogen gas as 1.0, the
sheet resistance after the process is reduced, but an increase rate
of the sheet resistance after the oxygen atmosphere exposure is
made larger. It is therefore expected that although the chlorines
and oxygen contained in the titanium nitride can be reduced by the
processing using only the hydrogen, dangling bonds remain, which
brings a state of easily being oxidized. Contrary to this, in a
case of processing with the ratio of the nitrogen gas to the
hydrogen within the processing gas as 1.0, no significant change
can be seen in the sheet resistance after the processing, and the
change in the resistance after the oxygen atmosphere exposure is
smaller. From this result, it is considered that the oxidation
resistance is improved by supplying the nitrogen to the surface of
the titanium nitride film. According to the above results, it can
be understood that both advantages of reduction of the sheet
resistance and the improvement in the oxidation resistance can be
achieved by mixing the gas containing the hydrogen atoms and the
nitrogen atom-containing gas and performing the plasma processing
thereby. Further, it can be understood that the processing should
be performed only with hydrogen in a case of simply improving the
sheet resistance, and should be performed only with nitrogen in a
case of simply improving the oxidation resistance.
[0077] (g) Further, it has been found that, similarly by using the
nitrogen gas (N.sub.2) and the ammonia gas (NH.sub.3) as the
processing gas, the residual amount of the chlorine atoms and the
residual amount of the oxygen atoms in the titanium nitride film
can be reduced, the electric resistance of the titanium nitride
film can be reduced, and the oxidation resistance can be
improved.
[0078] FIG. 8 is a graph comparing the sheet resistance ratio of
the thin film processed by changing the flow rates of the nitrogen
(N.sub.2) and the ammonia gas (NH.sub.3), the sheet resistance
ratio of the processed thin film after being exposed to the oxygen
atmosphere, and the sheet resistance ratio of the thin film that
has been exposed to the oxygen atmosphere without being subjected
to the aforementioned processing. Note that the exposure to the
oxygen (O.sub.2) atmosphere was performed for 120 seconds with the
O.sub.2 gas atmosphere, the gas pressure of 200 Pa, and the wafer
temperature of 450.degree. C. In any case, the value of the sheet
resistance of the titanium nitride film to which the aforementioned
substrate processing step has not been performed and that is before
being exposed to the oxygen atmosphere is set as 1 (reference).
[0079] As shown in FIG. 8, it can be understood that the sheet
resistance of the titanium nitride film can be reduced by
performing the aforementioned substrate processing step. Further,
it can be understood that the sheet resistance ratio becomes 0.89
or less in a range where the ratio of nitrogen gas to ammonia gas
in the processing gas is 0 or more and 0.87 or less, and the sheet
resistance ratio can more effectively be reduced, whereby the
refinement of integrated circuits and the property required in the
semiconductor device in recent years can be realized. Further, even
with the thin film that has been exposed to the oxygen atmosphere
after the nitriding, the sheet resistance ratio becomes about 0.92
or less when the ratio of nitrogen gas to ammonia gas in the
processing gas in performing the nitriding is in a range of 0 or
more and 0.87 or less, and the property can be maintained even if
an oxide film is formed on the titanium nitride film. Accordingly,
by performing the aforementioned substrate processing step, the
electric resistance of the titanium nitride film can be reduced.
Further, it can be understood that the oxidation resistance to
active oxygen species such as ozone (O.sub.3) or O.sub.2 plasma
used in forming a high-k film formed on the titanium nitride film
can be improved.
[0080] (h) Further, as a result of intensive studies, it has been
found that a property of the film formed on the silicon substrate
100 can be improved by changing the voltage Vpp to be applied to
the second electrode 217c. Hereinbelow, a modification of TiO.sub.x
and TiN.sub.x concentrations in the TiN film in a case with the
voltage Vpp of 50 V to 300 V, for example, when the change is
caused to take place with the voltage Vpplow (50 V) and the voltage
Vpphigh (300 V).
[0081] FIG. 9 is a graph comparing change rates of the TiO.sub.x
and TiN.sub.x concentrations in the film processed by changing the
voltage Vpp for the silicon substrate 100, and the TiO.sub.x and
TiN.sub.x concentrations in the film before the processing. The
TiO.sub.x and TiN.sub.x concentrations before the processing are
set as 1 (reference).
[0082] As shown in FIG. 9, it can be understood that, by applying
the aforementioned voltage Vpp, the TiO.sub.x concentration in the
titanium nitride film is reduced, and the TiN.sub.x concentration
is increased. Further, it can be understood that the increasing
amount of TiN.sub.x is larger than the reduction rate of TiO.sub.x.
Especially, it can be understood that TiO.sub.x is reduced and
TiN.sub.x is formed at a larger degree in the case of Vpphigh. By
applying the voltage Vpp in this manner, it becomes possible to
take in a large amount of N into the film while reducing O in the
film. With the large amount of N being taken in, the improvement in
the oxidation resistance of the film can be expected.
[0083] FIG. 10 is a graph showing a chlorine concentration in the
titanium nitride film upon performing the processing under the same
condition.
[0084] As shown in FIG. 10, it can be understood that the chlorine
concentration in the film is decreased by increasing the voltage
Vpp to be applied to the second electrode 217c. Thus, it is
considered that impurities in the film can be removed by applying
the voltage Vpp, and the electric property can be improved
similarly to the other examples as aforementioned.
[0085] From FIGS. 9 and 10, it is considered that hydrogen and
nitrogen are more likely to be drawn into the silicon substrate 100
by increasing the voltage Vpp to be applied to the second electrode
217c, whereby the oxygen and chlorine in the film are removed, and
the electric property can be improved while the oxidation
resistance of the titanium nitride film is improved by the nitrogen
being taken into the generated vacancies. Thus, even in a case of
forming a capacitor layer on the titanium nitride film by using
ozone (O.sub.3) and oxygen (O.sub.2) plasma, it is considered that
the titanium nitride film is prevented from being oxidized.
[0086] The aforementioned capacitor layer is a high-k film, and is
for example ZrO. Such a ZrO film is formed by using tetrakis
ethylmethylamino zirconium (TEMAZ) and ozone (O.sub.3) gas, in an
atmosphere of about 250.degree. C.
Other Embodiments of Invention
[0087] The embodiments have been described above specifically, but
the present invention is not limited to the aforementioned
embodiments and can be modified in various manners without
departing from the spirit of the present invention.
[0088] For example, in the aforementioned embodiments, the case of
processing the silicon substrate 100 on the surface of which the
titanium nitride film is formed has been described. However, the
invention is not limited to such a configuration, and may similarly
process other substrates containing chlorine atoms and metallic
atoms, such as a glass substrate on the surface of which the
titanium nitride film is formed.
[0089] Further, for example, in the aforementioned embodiments, the
case of using the mixed gas of the H.sub.2 gas and the N.sub.2 gas
and the case of using the mixed gas of the NH.sub.3 gas and the
N.sub.2 gas as the reactant gas have been described. However, the
invention is not limited to such configurations. Depending on
various conditions such as an amount of remaining chlorine in the
titanium nitride film, processing temperature, processing pressure,
and supply flow rate, the NH.sub.3 gas alone, the mixed gas of
NH.sub.3 gas and the H.sub.2 gas, the mixed gas of NH.sub.3 gas and
the N.sub.2 gas, the N.sub.2 gas alone, a monomethylhydrazine
(CH.sub.6N.sub.2) gas, or a gas obtained by mixing these gases at
arbitrary rates can be used as the reactant gas, for example.
Further, the gas containing nitrogen and the gas containing
hydrogen as aforementioned may alternately be supplied.
[0090] Further, in the aforementioned embodiments, although the
natural oxide film has been described as an example of the oxide
film formed on the substrate, the invention is not limited to this
example. For example, the natural oxide film may be removed before
moving the substrate into the present apparatus. In this case,
since the natural oxide film is absent from the substrate surface,
it becomes possible to surely remove the oxygen atoms mixed into
the substrate.
Preferred Embodiments
[0091] Hereinbelow, the preferred embodiments will supplementarily
be described.
Supplementary Note 1
[0092] According to one embodiment, there is provided a substrate
processing apparatus including:
[0093] a process chamber into which a substrate is carried, wherein
a chlorine atom-containing metal nitride film, in which a natural
oxide film is formed on a top side thereof, is formed on the
substrate;
[0094] a substrate support unit configured to support and heat the
substrate within the process chamber;
[0095] a gas supply unit configured to supply either or both of
nitrogen atom-containing gas and hydrogen atom-containing gas to an
inside of the process chamber;
[0096] a gas exhaust unit configured to exhaust the gas from the
inside of the process chamber;
[0097] a plasma generation unit configured to excite the nitrogen
atom-containing gas and the hydrogen atom-containing gas supplied
to the inside of the process chamber; and
[0098] a control unit configured to control the substrate support
unit, the gas supply unit, and the plasma generation unit.
Supplementary Note 2
[0099] Preferably, the metal nitride film described in the
Supplementary Note 1 is a titanium nitride film.
Supplementary Note 3
[0100] Preferably, the metal nitride film described in the
Supplementary Note 1 is a lower electrode of a capacitor.
Supplementary Note 4
[0101] Preferably, the capacitor described in the Supplementary
Note 3 is a high-k film.
Supplementary Note 5
[0102] Preferably, the plasma generation unit described in the
Supplementary Note 1 is provided to generate plasma within the
process chamber.
Supplementary Note 6
[0103] Preferably, the nitrogen atom-containing gas described in
the Supplementary Note 1 is any of a nitrogen gas, an ammonia gas,
and a monomethylhydrazine gas, and the hydrogen atom-containing gas
is any of a hydrogen gas, an ammonia gas, and a monomethylhydrazine
gas.
Supplementary Note 7
[0104] Preferably, a ratio of a nitrogen gas to a hydrogen gas
supplied into the process chamber described in the Supplementary
Note 1 is in a range of 0 or more and 0.75 or less.
Supplementary Note 8
[0105] More preferably, the ratio of the nitrogen gas to the
hydrogen gas supplied into the process chamber described in the
Supplementary Note 1 is in a range of larger than 0 and 0.75 or
less.
Supplementary Note 9
[0106] Preferably, a ratio of the nitrogen gas to a gas containing
nitrogen and hydrogen supplied into the process chamber described
in the Supplementary Note 1 is in a range of 0 or more and 0.87 or
less.
Supplementary Note 10
[0107] According to another embodiment, there is provided a method
of manufacturing a semiconductor device, the method including:
[0108] carrying a substrate into a process chamber and supporting
the substrate by a substrate support unit, wherein a chlorine
atom-containing metal nitride film, in which a natural oxide film
is formed on a top side thereof, is formed on the substrate;
[0109] heating the substrate by the substrate support unit;
[0110] supplying nitrogen atom-containing gas and hydrogen
atom-containing gas by a gas supply unit to an inside of the
process chamber and exhausting the process chamber by a gas exhaust
unit; and
[0111] exciting the nitrogen atom-containing gas and the hydrogen
atom-containing gas supplied into the process chamber by a plasma
generation unit.
Supplementary Note 11
[0112] According to yet another embodiment, there is provided a
method of manufacturing a semiconductor device, the method
including:
[0113] carrying a substrate into a process chamber, wherein a
chlorine atom-containing metal nitride film, in which a natural
oxide film is formed on a top side thereof, is formed on the
substrate;
[0114] processing the substrate within the process chamber with a
reactant gas containing excited nitrogen atoms; and
[0115] taking out the substrate from the process chamber.
Supplementary Note 12
[0116] Preferably, the reactant gas described in the Supplementary
Note 11 further contains hydrogen atoms.
Supplementary Note 13
[0117] Preferably, the metal nitride film described in the
Supplementary Note 11 is a titanium-containing film.
Supplementary Note 14
[0118] Preferably, the reactant gas described in the Supplementary
Note 11 is an ammonia gas, or a mixed gas of nitrogen components
and ammonia components.
Supplementary Note 15
[0119] According to yet another embodiment, the reactant gas
described in the Supplementary Notes 1 to 14 is diluted with a
noble gas.
Supplementary Note 16
[0120] According to yet another embodiment, there is provided a
substrate processing apparatus including:
[0121] a process chamber into which a substrate is carried, wherein
a chlorine atom-containing metal nitride film, in which a natural
oxide film is formed on a top side thereof, is formed on the
substrate;
[0122] a gas supply unit configured to supply a reactant gas to an
inside of the process chamber;
[0123] a plasma generation unit configured to excite the reactant
gas within the process chamber; and
[0124] a control unit configured to control the gas supply unit and
the plasma generation unit so that the substrate is processed
within the process chamber with the reactant gas containing excited
nitrogen atoms.
Supplementary Note 17
[0125] According to yet another embodiment, there is provided a
substrate processing apparatus including:
[0126] a process chamber into which a substrate is carried, wherein
a chlorine atom-containing metal nitride film, in which a natural
oxide film is formed on a top side thereof, is formed on the
substrate;
[0127] a substrate support unit configured to support and heat the
substrate within the process chamber;
[0128] a gas supply unit configured to supply a nitrogen
atom-containing first processing gas and a hydrogen atom-containing
second processing gas alternately to an inside of the process
chamber;
[0129] a gas exhaust unit configured to exhaust the process
chamber;
[0130] a plasma generation unit configured to excite the first
processing gas and the second processing gas supplied into the
process chamber; and
[0131] a control unit configured to control the substrate support
unit, the gas supply unit, the gas exhaust unit, and the plasma
generation unit.
Supplementary Note 18
[0132] According to yet another embodiment, the substrate support
unit described in the Supplementary Notes 1 to 17 has a second
electrode provided thereon, and a voltage Vpp is applied to the
substrate.
INDUSTRIAL APPLICABILITY
[0133] According to the substrate processing apparatus and the
method of manufacturing a semiconductor device of the embodiment,
the residual amounts of the chlorine atoms and the oxygen atoms in
the metal nitride film can be reduced in the temperature range that
does not deteriorate the property of other films adjacent to the
metal nitride film, and the oxidation resistance can be improved
while the property of the metal nitride film is improved.
REFERENCE SIGNS LIST
[0134] 100 Silicon substrate (substrate) [0135] 201 Process chamber
[0136] 121 Controller (control unit)
* * * * *